Acute kidney injury (AKI) is common in hospitalized individuals, associated with adverse outcomes and increased cost. Continuous renal replacement therapy (CRRT) is used to treat critically ill patients with AKI, of which the cost in acute phase is higher than that of intermittent renal replacement therapy (IRRT). However, if treatment for subsequent chronic kidney disease or dialysis dependency following AKI is also considered, CRRT might be more cost-effective than IRRT. In this editorial, the cost and health economic evaluation of CRRT for critically ill patients is discussed.